Subject: big bro under the hood
Black Boxes Come
Down to Earth
Once Only for Plane Crashes, Devices Now
on Cars, Trains, Buses
March 16, 2000
By Ann Ferrar
DETROIT (APBnews.com)
-- They are the elusive
objects investigators seek
after an airplane crashes.
Black boxes tell the hidden
story: what was going on,
what the pilot was doing
and what condition the
airplane was in before the
accident. And now they are
finding their way into cars.
The technical name for the
devices is event data
retrieval units (EDRUs).
They work continuously, but
only save in memory the data recorded in the
last five seconds before a crash. At impact,
the device also records what researchers call
delta-v, the velocity of the crash itself. (A
crash into a brick wall, for example, at 20
mph, would have a delta-v of 20).
What EDRUs do is yield critical information
about crashes, especially when there are no
bystanders available. "This is the only
unbiased eyewitness available," said John
Hinch, a research engineer at the National
Highway Transportation Safety Administration
(NHTSA).
According to the NHTSA, there are 6,335,000
severe car crashes a year, or 17,350 a day, in
the United States.
"Cars are designed in labs and tested with
certain benchmarks against walls, curbs and
potholes," Hinch said. "But in the real world ...
we really don't know how a car will behave in
every situation. The devices provide us with
real-life data that will help manufacturers
develop better crash sensor technology."
The data also can help police and insurance
companies figure out what happened, Hinch
said.
Latest models have them
General Motors Corp. (GM) and Ford both
have begun installing black boxes in their
latest models. Since 1999, EDRUs have been
put in the airbag sensor systems of nine of
GM's model lines to record pre-crash vehicle
speed, engine rpm, whether or not the driver
applied the brake and how much foot pressure
was applied on the gas pedal.
The black boxes are put under the driver or
passenger seat or under the dashboard and
have been built into the Pontiac Firebird;
Chevy Camaro and Corvette; Buick Park
Avenue, Regal and Century; and Cadillac
SeVille, El Dorado, and DeVille.
The latest EDRUs are the
third generation of a
device first installed by
GM in the late 1980s. The
early version recorded
whether the driver had his
seatbelt on and how much
time elapsed between
impact and airbag
deployment. The second
version, introduced on
some cars in 1994, also
recorded the velocity of
the crash.
Secrecy limits data
Ford has installed what it calls a Personal
Safety System, a limited version of the EDRU,
on its Taurus and Mercury Sable model lines.
Ford's system uses sensors to analyze certain
crash conditions and automatically deploy the
most suitable safety devices for the situation,
including dual-stage airbags for the driver and
front-seat passenger.
GM, however, is the first manufacturer to
make the data accessible to consumers. This
spring, a tool will be introduced that will
enable consumers to retrieve the data
themselves and download it onto a computer.
Until then, such information is proprietary --
available only to the manufacturers and to
NHTSA with the car owner's permission.
This secrecy is the reason, partly, why not
much data exists on the devices. NHTSA
expects to gather data on several hundred
cases within the next couple of years. Hinch
predicts that most or all GM cars will have the
devices by the end of 2002. The government
has so far denied petitions to make event
recorders mandatory.
"We need to study them more and ascertain
their usefulness," Hinch said.
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